XML-RPC is a Remote Procedure Call method that uses XML passed via HTTP(S) as a
transport. With it, a client can call methods with parameters on a remote
server (the server is named by a URI) and get back structured data. This module
supports writing XML-RPC client code; it handles all the details of translating
between conformable Python objects and XML on the wire.

A ServerProxy instance is an object that manages communication with a
remote XML-RPC server. The required first argument is a URI (Uniform Resource
Indicator), and will normally be the URL of the server. The optional second
argument is a transport factory instance; by default it is an internal
SafeTransport instance for https: URLs and an internal HTTP
Transport instance otherwise. The optional third argument is an
encoding, by default UTF-8. The optional fourth argument is a debugging flag.

The following parameters govern the use of the returned proxy instance.
If allow_none is true, the Python constant None will be translated into
XML; the default behaviour is for None to raise a TypeError. This is
a commonly-used extension to the XML-RPC specification, but isn’t supported by
all clients and servers; see http://ontosys.com/xml-rpc/extensions.php
for a description.
The use_builtin_types flag can be used to cause date/time values
to be presented as datetime.datetime objects and binary data to be
presented as bytes objects; this flag is false by default.
datetime.datetime, bytes and bytearray objects
may be passed to calls.
The obsolete use_datetime flag is similar to use_builtin_types but it
applies only to date/time values.

Both the HTTP and HTTPS transports support the URL syntax extension for HTTP
Basic Authentication: http://user:pass@host:port/path. The user:pass
portion will be base64-encoded as an HTTP ‘Authorization’ header, and sent to
the remote server as part of the connection process when invoking an XML-RPC
method. You only need to use this if the remote server requires a Basic
Authentication user and password. If an HTTPS URL is provided, context may
be ssl.SSLContext and configures the SSL settings of the underlying
HTTPS connection.

The returned instance is a proxy object with methods that can be used to invoke
corresponding RPC calls on the remote server. If the remote server supports the
introspection API, the proxy can also be used to query the remote server for the
methods it supports (service discovery) and fetch other server-associated
metadata.

Types that are conformable (e.g. that can be marshalled through XML),
include the following (and except where noted, they are unmarshalled
as the same Python type):

This is the full set of data types supported by XML-RPC. Method calls may also
raise a special Fault instance, used to signal XML-RPC server errors, or
ProtocolError used to signal an error in the HTTP/HTTPS transport layer.
Both Fault and ProtocolError derive from a base class called
Error. Note that the xmlrpc client module currently does not marshal
instances of subclasses of built-in types.

When passing strings, characters special to XML such as <, >, and &
will be automatically escaped. However, it’s the caller’s responsibility to
ensure that the string is free of characters that aren’t allowed in XML, such as
the control characters with ASCII values between 0 and 31 (except, of course,
tab, newline and carriage return); failing to do this will result in an XML-RPC
request that isn’t well-formed XML. If you have to pass arbitrary bytes
via XML-RPC, use bytes or bytearray classes or the
Binary wrapper class described below.

Changed in version 3.6: Added support of type tags with prefixes (e.g. ex:nil).
Added support of unmarsalling additional types used by Apache XML-RPC
implementation for numerics: i1, i2, i8, biginteger,
float and bigdecimal.
See http://ws.apache.org/xmlrpc/types.html for a description.

A ServerProxy instance has a method corresponding to each remote
procedure call accepted by the XML-RPC server. Calling the method performs an
RPC, dispatched by both name and argument signature (e.g. the same method name
can be overloaded with multiple argument signatures). The RPC finishes by
returning a value, which may be either returned data in a conformant type or a
Fault or ProtocolError object indicating an error.

Servers that support the XML introspection API support some common methods
grouped under the reserved system attribute:

This method takes one parameter, the name of a method implemented by the XML-RPC
server. It returns an array of possible signatures for this method. A signature
is an array of types. The first of these types is the return type of the method,
the rest are parameters.

Because multiple signatures (ie. overloading) is permitted, this method returns
a list of signatures rather than a singleton.

Signatures themselves are restricted to the top level parameters expected by a
method. For instance if a method expects one array of structs as a parameter,
and it returns a string, its signature is simply “string, array”. If it expects
three integers and returns a string, its signature is “string, int, int, int”.

If no signature is defined for the method, a non-array value is returned. In
Python this means that the type of the returned value will be something other
than list.

This method takes one parameter, the name of a method implemented by the XML-RPC
server. It returns a documentation string describing the use of that method. If
no such string is available, an empty string is returned. The documentation
string may contain HTML markup.

This class may be initialized with seconds since the epoch, a time
tuple, an ISO 8601 time/date string, or a datetime.datetime
instance. It has the following methods, supported mainly for internal
use by the marshalling/unmarshalling code:

Create an object used to boxcar method calls. server is the eventual target of
the call. Calls can be made to the result object, but they will immediately
return None, and only store the call name and parameters in the
MultiCall object. Calling the object itself causes all stored calls to
be transmitted as a single system.multicall request. The result of this call
is a generator; iterating over this generator yields the individual
results.

Convert params into an XML-RPC request. or into a response if methodresponse
is true. params can be either a tuple of arguments or an instance of the
Fault exception class. If methodresponse is true, only a single value
can be returned, meaning that params must be of length 1. encoding, if
supplied, is the encoding to use in the generated XML; the default is UTF-8.
Python’s None value cannot be used in standard XML-RPC; to allow using
it via an extension, provide a true value for allow_none.

Convert an XML-RPC request or response into Python objects, a (params,methodname). params is a tuple of argument; methodname is a string, or
None if no method name is present in the packet. If the XML-RPC packet
represents a fault condition, this function will raise a Fault exception.
The use_builtin_types flag can be used to cause date/time values to be
presented as datetime.datetime objects and binary data to be
presented as bytes objects; this flag is false by default.

The obsolete use_datetime flag is similar to use_builtin_types but it
applies only to date/time values.